Gamma-ray Burst 180115A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:17:18 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     805318,   Seg_Num: 0
GRB_RA:           12.073d {+00h 48m 18s} (J2000),
                  12.298d {+00h 49m 12s} (current),
                  11.449d {+00h 45m 48s} (1950)
GRB_DEC:         -15.608d {-15d 36' 27"} (J2000),
                 -15.510d {-15d 30' 34"} (current),
                 -15.880d {-15d 52' 48"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=1234 [image_cnts]
TRIGGER_DUR:     64.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        18133 TJD;    15 DOY;   18/01/15
GRB_TIME:        15363.68 SOD {04:16:03.68} UT
GRB_PHI:         129.63 [deg]
GRB_THETA:        27.19 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.76 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  -2  +0  +0 -32  +0 
SUN_POSTN:       296.90d {+19h 47m 35s}  -21.14d {-21d 08' 10"}
SUN_DIST:         71.16 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.45d {+18h 17m 49s}  -19.92d {-19d 55' 20"}
MOON_DIST:        91.86 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.15,-78.46 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        4.72,-19.09 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 180.60,-20.62 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:18:39 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     805318,   Seg_Num: 0
GRB_RA:           12.0384d {+00h 48m 09.21s} (J2000),
                  12.2636d {+00h 49m 03.27s} (current),
                  11.4139d {+00h 45m 39.32s} (1950)
GRB_DEC:         -15.6274d {-15d 37' 38.6"} (J2000),
                 -15.5292d {-15d 31' 45.1"} (current),
                 -15.9000d {-15d 53' 59.9"} (1950)
GRB_ERROR:       7.0 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       3.57e-10 [erg/cm2/sec]
GRB_SIGNIF:      4.69 [sigma]
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15494.77 SOD {04:18:14.77} UT,   131.1 [sec] since BAT Trigger Time
TAM[0-3]:        327.66 237.14 261.67 243.58
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       296.90d {+19h 47m 35s}  -21.14d {-21d 08' 09"}
SUN_DIST:         71.12 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.47d {+18h 17m 52s}  -19.92d {-19d 55' 22"}
MOON_DIST:        91.81 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      118.97,-78.47 [deg] galactic lon,lat of the burst
ECL_COORDS:        4.68,-19.09 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 2.32 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:18:49 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     805318,   Seg_Num: 0
GRB_RA:           12.0384d {+00h 48m 09.2s} (J2000),
                  12.2636d {+00h 49m 03.2s} (current),
                  11.4139d {+00h 45m 39.3s} (1950)
GRB_DEC:         -15.6274d {-15d 37' 38.6"} (J2000),
                 -15.5292d {-15d 31' 45.1"} (current),
                 -15.9000d {-15d 53' 59.9"} (1950)
GRB_ERROR:       6.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       22 [cnts]
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15494.77 SOD {04:18:14.77} UT,   131.1 [sec] since BAT Trigger Time
CENTROID_X:      282.08,  raw= 282  [pixels]
CENTROID_Y:      319.07,  raw= 319  [pixels]
ROLL:            252.56 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   48.74
GRB_POS_XRT_Z:   -57.31
IMAGE_URL:       sw00805318000msxps_rw.img
SUN_POSTN:       296.90d {+19h 47m 35s}  -21.14d {-21d 08' 09"}
SUN_DIST:         71.12 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.47d {+18h 17m 52s}  -19.92d {-19d 55' 22"}
MOON_DIST:        91.81 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      118.97,-78.47 [deg] galactic lon,lat of the burst
ECL_COORDS:        4.68,-19.09 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:18:52 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     805318,   Seg_Num: 0
GRB_RA:           12.0384d {+00h 48m 09.2s} (J2000),
                  12.2636d {+00h 49m 03.2s} (current),
                  11.4139d {+00h 45m 39.3s} (1950)
GRB_DEC:         -15.6274d {-15d 37' 38.6"} (J2000),
                 -15.5292d {-15d 31' 45.1"} (current),
                 -15.9000d {-15d 53' 59.9"} (1950)
GRB_ERROR:       6.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       22 [cnts]
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15494.77 SOD {04:18:14.77} UT,   131.1 [sec] since BAT Trigger Time
CENTROID_X:      282.08,  raw= 282  [pixels]
CENTROID_Y:      319.07,  raw= 319  [pixels]
ROLL:            252.56 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   48.74
GRB_POS_XRT_Z:   -57.31
IMAGE_URL:       sw00805318000msxps_rw.img
SUN_POSTN:       296.90d {+19h 47m 35s}  -21.14d {-21d 08' 09"}
SUN_DIST:         71.12 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.47d {+18h 17m 52s}  -19.92d {-19d 55' 22"}
MOON_DIST:        91.81 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      118.97,-78.47 [deg] galactic lon,lat of the burst
ECL_COORDS:        4.68,-19.09 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:19:53 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     805318,   Seg_Num: 0
GRB_RA:           12.073d {+00h 48m 18s} (J2000),
                  12.298d {+00h 49m 12s} (current),
                  11.449d {+00h 45m 48s} (1950)
GRB_DEC:         -15.608d {-15d 36' 27"} (J2000),
                 -15.510d {-15d 30' 34"} (current),
                 -15.880d {-15d 52' 48"} (1950)
GRB_DATE:        18133 TJD;    15 DOY;   18/01/15
GRB_TIME:        15363.68 SOD {04:16:03.68} UT
TRIGGER_INDEX:   20000
GRB_PHI:         129.63 [deg]
GRB_THETA:        27.19 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.76 [sigma]
LC_URL:          sw00805318000msb.lc
SUN_POSTN:       296.90d {+19h 47m 36s}  -21.14d {-21d 08' 09"}
SUN_DIST:         71.16 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.48d {+18h 17m 54s}  -19.92d {-19d 55' 23"}
MOON_DIST:        91.84 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.15,-78.46 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        4.72,-19.09 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is an image trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 180.60,-20.62 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:21:28 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.050d {+00h 48m 12s} (J2000)
POINT_DEC:       -15.610d {-15d 36' 35"} (J2000)
POINT_ROLL:      252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15504.18 SOD {04:18:24.18} UT,   140.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.198
N_STARS:         21
X_OFFSET:        312 [pixels]
Y_OFFSET:        592 [pixels]
X_MAX:           1271 [pixels]
Y_MAX:           1551 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00805318000msufc0140.fits
SUN_POSTN:       296.90d {+19h 47m 36s}  -21.14d {-21d 08' 08"}
SUN_DIST:         71.13 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.49d {+18h 17m 58s}  -19.92d {-19d 55' 25"}
MOON_DIST:        91.81 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.03,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:21:42 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.050d {+00h 48m 12s} (J2000)
POINT_DEC:       -15.610d {-15d 36' 35"} (J2000)
POINT_ROLL:      252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15504.18 SOD {04:18:24.18} UT,   140.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.198
N_STARS:         21
X_OFFSET:        312 [pixels]
Y_OFFSET:        592 [pixels]
X_MAX:           1271 [pixels]
Y_MAX:           1551 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00805318000msufc0140.fits
SUN_POSTN:       296.90d {+19h 47m 36s}  -21.14d {-21d 08' 08"}
SUN_DIST:         71.13 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.49d {+18h 17m 58s}  -19.92d {-19d 55' 25"}
MOON_DIST:        91.81 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.03,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:23:06 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.050d {+00h 48m 12s} (J2000)
POINT_DEC:       -15.610d {-15d 36' 35"} (J2000)
ROLL:            252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15504.18 SOD {04:18:24.18} UT,   140.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     537682724
X_OFFSET:        834 [pixels]
Y_OFFSET:        730 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       994
Y_GRB_POS:       890
BINNING_INDEX:   1
IM_URL:          sw00805318000msuni0161.fits
SUN_POSTN:       296.90d {+19h 47m 36s}  -21.14d {-21d 08' 07"}
SUN_DIST:         71.13 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.50d {+18h 18m 01s}  -19.92d {-19d 55' 27"}
MOON_DIST:        91.80 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.03,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:23:20 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.050d {+00h 48m 12s} (J2000)
POINT_DEC:       -15.610d {-15d 36' 35"} (J2000)
ROLL:            252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15504.18 SOD {04:18:24.18} UT,   140.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     537682724
X_OFFSET:        834 [pixels]
Y_OFFSET:        730 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       994
Y_GRB_POS:       890
BINNING_INDEX:   1
IM_URL:          sw00805318000msuni0161.fits
SUN_POSTN:       296.90d {+19h 47m 36s}  -21.14d {-21d 08' 07"}
SUN_DIST:         71.13 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.51d {+18h 18m 02s}  -19.92d {-19d 55' 27"}
MOON_DIST:        91.79 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.03,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:24:36 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     805318,   Seg_Num: 0
GRB_RA:           12.0385d {+00h 48m 09.24s} (J2000),
                  12.2637d {+00h 49m 03.29s} (current),
                  11.4140d {+00h 45m 39.34s} (1950)
GRB_DEC:         -15.6305d {-15d 37' 49.7"} (J2000),
                 -15.5323d {-15d 31' 56.3"} (current),
                 -15.9031d {-15d 54' 11.1"} (1950)
GRB_ERROR:       0.8 [arcsec radius, statistical only]
GRB_MAG:         17.54 +/- 0.14 [mag]
FILTER:          10, White
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15501.00 SOD {04:18:21.00} UT,   137.3 [sec] since BAT Trigger Time
SUN_POSTN:       296.90d {+19h 47m 36s}  -21.14d {-21d 08' 06"}
SUN_DIST:         71.12 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.52d {+18h 18m 04s}  -19.92d {-19d 55' 28"}
MOON_DIST:        91.77 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      118.97,-78.48 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        4.68,-19.09 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The UVOT position is 10.8 arcsec from the XRT position.  
COMMENTS:        Result based on Genie data.  
COMMENTS:        Notice generated automatically.

GCN Circular #22335
J. K. Cannizzo (NASA/UMBC), J. R. Cummings (NASA/UMBC), A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC), A. Deich (PSU), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 04:16:03 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 180115A (trigger=805318). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 12.073, -15.608 which is
```
   RA(J2000) = 00h 48m 18s
   Dec(J2000) = -15d 36' 27"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is usual for an image trigger, the immediately available light curve shows no obvious variation.
The XRT began observing the field at 04:18:14.7 UT, 131.1 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 12.03953, -15.62924 which is equivalent to:
```
   RA(J2000)  = 00h 48m 09.49s
   Dec(J2000) = -15d 37' 45.3"
```
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 138 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. No spectrum from the promptly downlinked event data is yet available to determine the column density.
The initial flux in the 2.5 s image was 3.57e-10 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 140 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =	00:48:09.25 =  12.03856
  DEC(J2000) = -15:37:49.8  = -15.63051
```
with a 90%-confidence error radius of about 0.75 arc sec. This position is 5.6 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.54 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02.
Burst Advocate for this burst is J. K. Cannizzo (cannizzo AT milkyway.gsfc.nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:29:22 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.048d {+00h 48m 11s} (J2000)
POINT_DEC:       -15.609d {-15d 36' 31"} (J2000)
POINT_ROLL:      252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15662.40 SOD {04:21:02.40} UT,   298.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.782
N_STARS:         13
X_OFFSET:        514 [pixels]
Y_OFFSET:        410 [pixels]
X_MAX:           1473 [pixels]
Y_MAX:           1369 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00805318000msufc0298.fits
SUN_POSTN:       296.91d {+19h 47m 37s}  -21.13d {-21d 08' 04"}
SUN_DIST:         71.13 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.56d {+18h 18m 14s}  -19.93d {-19d 55' 34"}
MOON_DIST:        91.74 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.02,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:29:38 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.048d {+00h 48m 11s} (J2000)
POINT_DEC:       -15.609d {-15d 36' 31"} (J2000)
POINT_ROLL:      252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15662.40 SOD {04:21:02.40} UT,   298.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.782
N_STARS:         13
X_OFFSET:        514 [pixels]
Y_OFFSET:        410 [pixels]
X_MAX:           1473 [pixels]
Y_MAX:           1369 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00805318000msufc0298.fits
SUN_POSTN:       296.91d {+19h 47m 37s}  -21.13d {-21d 08' 04"}
SUN_DIST:         71.13 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.56d {+18h 18m 15s}  -19.93d {-19d 55' 34"}
MOON_DIST:        91.74 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.02,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:29:57 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     805318,   Seg_Num: 0
GRB_RA:           12.0397d {+00h 48m 09.52s} (J2000),
                  12.2649d {+00h 49m 03.58s} (current),
                  11.4152d {+00h 45m 39.63s} (1950)
GRB_DEC:         -15.6303d {-15d 37' 49.0"} (J2000),
                 -15.5321d {-15d 31' 55.6"} (current),
                 -15.9029d {-15d 54' 10.4"} (1950)
GRB_ERROR:       2.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15589.00 SOD {04:19:49.00} UT,   225.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       296.91d {+19h 47m 37s}  -21.13d {-21d 08' 04"}
SUN_DIST:         71.11 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.56d {+18h 18m 16s}  -19.93d {-19d 55' 34"}
MOON_DIST:        91.73 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      118.98,-78.48 [deg] galactic lon,lat of the burst
ECL_COORDS:        4.68,-19.09 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.11% < P(seren) < 0.58%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:30:45 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.048d {+00h 48m 11s} (J2000)
POINT_DEC:       -15.609d {-15d 36' 31"} (J2000)
ROLL:            252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15662.40 SOD {04:21:02.40} UT,   298.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     537682882
X_OFFSET:        834 [pixels]
Y_OFFSET:        730 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       994
Y_GRB_POS:       890
BINNING_INDEX:   1
IM_URL:          sw00805318000msuni0319.fits
SUN_POSTN:       296.91d {+19h 47m 38s}  -21.13d {-21d 08' 04"}
SUN_DIST:         71.13 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.57d {+18h 18m 17s}  -19.93d {-19d 55' 35"}
MOON_DIST:        91.73 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.02,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:30:59 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.048d {+00h 48m 11s} (J2000)
POINT_DEC:       -15.609d {-15d 36' 31"} (J2000)
ROLL:            252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  15662.40 SOD {04:21:02.40} UT,   298.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     537682882
X_OFFSET:        834 [pixels]
Y_OFFSET:        730 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       994
Y_GRB_POS:       890
BINNING_INDEX:   1
IM_URL:          sw00805318000msuni0319.fits
SUN_POSTN:       296.91d {+19h 47m 38s}  -21.13d {-21d 08' 03"}
SUN_DIST:         71.13 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.57d {+18h 18m 18s}  -19.93d {-19d 55' 36"}
MOON_DIST:        91.73 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.02,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:37:25 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.048d {+00h 48m 11s} (J2000)
POINT_DEC:       -15.609d {-15d 36' 31"} (J2000)
POINT_ROLL:      252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  16243.19 SOD {04:30:43.19} UT,   879.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.974
N_STARS:         47
X_OFFSET:        274 [pixels]
Y_OFFSET:        170 [pixels]
X_MAX:           1713 [pixels]
Y_MAX:           1609 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00805318000msufc0879.fits
SUN_POSTN:       296.91d {+19h 47m 39s}  -21.13d {-21d 08' 01"}
SUN_DIST:         71.12 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.63d {+18h 18m 31s}  -19.93d {-19d 55' 43"}
MOON_DIST:        91.68 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.02,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:37:38 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.048d {+00h 48m 11s} (J2000)
POINT_DEC:       -15.609d {-15d 36' 31"} (J2000)
POINT_ROLL:      252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  16243.19 SOD {04:30:43.19} UT,   879.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.974
N_STARS:         47
X_OFFSET:        274 [pixels]
Y_OFFSET:        170 [pixels]
X_MAX:           1713 [pixels]
Y_MAX:           1609 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00805318000msufc0879.fits
SUN_POSTN:       296.91d {+19h 47m 39s}  -21.13d {-21d 08' 00"}
SUN_DIST:         71.12 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.63d {+18h 18m 32s}  -19.93d {-19d 55' 43"}
MOON_DIST:        91.68 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.02,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:38:19 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.048d {+00h 48m 11s} (J2000)
POINT_DEC:       -15.609d {-15d 36' 31"} (J2000)
ROLL:            252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  16243.19 SOD {04:30:43.19} UT,   879.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     537683463
X_OFFSET:        833 [pixels]
Y_OFFSET:        729 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       993
Y_GRB_POS:       889
BINNING_INDEX:   1
IM_URL:          sw00805318000msuni0900.fits
SUN_POSTN:       296.91d {+19h 47m 39s}  -21.13d {-21d 08' 00"}
SUN_DIST:         71.12 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.64d {+18h 18m 33s}  -19.93d {-19d 55' 44"}
MOON_DIST:        91.67 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.02,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 15 Jan 18 04:38:33 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     805318,   Seg_Num: 0
POINT_RA:         12.048d {+00h 48m 11s} (J2000)
POINT_DEC:       -15.609d {-15d 36' 31"} (J2000)
ROLL:            252.562d
IMG_START_DATE:  18133 TJD;    15 DOY;   18/01/15
IMG_START_TIME:  16243.19 SOD {04:30:43.19} UT,   879.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     537683463
X_OFFSET:        833 [pixels]
Y_OFFSET:        729 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       993
Y_GRB_POS:       889
BINNING_INDEX:   1
IM_URL:          sw00805318000msuni0900.fits
SUN_POSTN:       296.91d {+19h 47m 39s}  -21.13d {-21d 08' 00"}
SUN_DIST:         71.12 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      274.64d {+18h 18m 34s}  -19.93d {-19d 55' 44"}
MOON_DIST:        91.67 [deg]
MOON_ILLUM:      3 [%]
GAL_COORDS:      119.02,-78.46 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        4.70,-19.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #22337
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 3943 s of XRT Photon Counting mode data and 7 UVOT images for GRB 180115A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 12.03876, -15.63065 which is equivalent to:
```
RA (J2000): 00h 48m 9.30s
Dec (J2000): -15d 37' 50.3"
```
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #22338
J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), D.N. Burrows (PSU) and J.K. Cannizzo report on behalf of the Swift-XRT team:
We have analysed 6.6 ks of XRT data for GRB 180115A (Cannizzo et al. GCN Circ. 22335), from 137 s to 13.1 ks after the BAT trigger. The data comprise 86 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 22337).
The light curve can be modelled with an initial power-law decay with an index of alpha=3.6 (+0.6, -0.5), followed by a break at T+269 s to an alpha of 0.71 (+/-0.04).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.26 (+0.13, -0.12). The best-fitting absorption column is consistent with the Galactic value of 1.7 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.94 (+0.12, -0.11) and a best-fitting absorption column of 3.6 (+2.4, -2.0) x 10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.3 x 10^-11 (3.6 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     3.6 (+2.4, -2.0) x 10^20 cm^-2
Galactic foreground: 1.7 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.94 (+0.12, -0.11)
```
If the light curve continues to decay with a power-law decay index of 0.71, the count rate at T+24 hours will be 0.025 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.3 x 10^-13 (9.0 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00805318.
This circular is an official product of the Swift-XRT team.
GCN Circular #22340
K. L. Murata, R. Itoh,T. Yoshii, Y. Tachibana, S. Harita, K. Morita, T. Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We searched for the optical counterpart of GRB 180115A (Cannizzo et al., GCN Circular #22335) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2018-01-15 09:25:40 UT. We did not find the previously reported candidate afterglow (Cannizzo et al., GCN Circular #22335) in all three bands. We obtained following limits for the magnitudes.
```
T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
-------------------------------------------------------------------------------------------------------
~5.16       10:06:44      4320       >19.8    >19.6     >19.0
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
```
We used GSC2.3 catalog for flux calibration.
GCN Circular #22345
Z. Cano (HETH/IAA-CSIC), K. E. Heintz (Univ. Iceland & DARK/NBI), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), I. Marquez & S. Cazzoli (IAA-CSIC) report on behalf of a larger collaboration:
We observed the field of GRB 180115A (Cannizzo et al.; GCN Circ. 22335) with the 2.5-m Nordic Optical Telescope equipped with ALFOSC, starting at 19:40:26 UT on 15 January 2017. We obtained 3x300 s in the r-band. In our co-added image a faint, new object is detected in the enhanced XRT error circle (Goad et al.; GCN Circ. 22337), with an apparent magnitude of r = 21.3 +- 0.1, at a mean post-explosion epoch of +15.53 hours. The calibration was performed using local Pan-STARRS standards in the GRB field. This apparent magnitude is not corrected for foreground extinction.
GCN Circular #22346
A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), Z. Cano, L. Izzo, C.C. Thoene, D.A. Kann (HETH/IAA-CSIC), N. Castro-Rodriguez (Grantecan, IAC, ULL), D. Perez Valladares (Grantecan) report on behalf of a larger collaboration:
We observed the afterglow of GRB 180115A (Cannizzo et al. GCN 22335, Cano et al. GCN 22345) with OSIRIS at the 10.4m GTC telescope. The observation consisted of 3x900s exposure with grism R1000B, covering the range between 3700 and 7800 Angstrom and was performed under bad seeing conditions.
The observation started at 20:32 UT (16.28 hr after the burst), and the acquisition image shows the afterglow at r=21.2+/-0.2. The spectrum shows a weak continuum over all the spectral range. The low signal to noise ratio of the spectrum only allows us to detect a single broad spectral feature that we identify as Lyman alpha at a redshift of 2.487.
GCN Circular #22348
S. D. Barthelmy (GSFC), J. K. Cannizzo (NASA/UMBC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+446 sec from the recent telemetry downlink, we report further analysis of BAT GRB 180115A (trigger #805318) (Cannizzo et al., GCN Circ. 22335). The BAT ground-calculated position is RA, Dec = 12.040, -15.632 deg which is
```
  RA(J2000)  =  00h 48m 09.6s
  Dec(J2000) = -15d 37' 55.0"
```
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 57%.
The mask-weighted light curve shows a multi-peaked structure that starts at ~ T+25 s and ends at ~T+70 s. The main peak occurs at ~T+66 s. T90 (15-350 keV) is 40.9 +- 3.0 sec (estimated error including systematics).
The time-averaged spectrum from T+26.49 to T+70.28 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.66 +- 0.22. The fluence in the 15-150 keV band is 7.6 +- 1.1 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+65.96 sec in the 15-150 keV band is 0.6 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/805318/BA/
GCN Circular #22357
F. E. Marshall (NASA/GSFC) and J. K. Cannizzo (NASA/UMBC) report on behalf of the Swift/UVOT team:
Additional observations of the optical afterglow of GRB 180115A discovered with Swift/UVOT (Cannizzo et al., GCN Circ. 22335) reveal an initially brightening and then fading source. The source is not detected in any of the UV filters, consistent with the redshift of 2.487 reported by de Ugarte Postigo et al. (GCN Circ. 22346).
The preliminary UVOT position is:
```
    RA  (J2000) =  00:48:09.27 =  12.03862 (deg.)
    Dec (J2000) = -15:37:49.9  = -15.63054 (deg.)
```
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white              140          290          147         17.61 +/- 0.04
white              753          773           20         16.95 +/- 0.07
white             5663         5863          197         19.18 +/- 0.08
v                  628          648           20         16.50 +/- 0.16
b                  554          574           20         16.93 +/- 0.11
u                  299          548          246         16.32 +/- 0.04
w1                1109        13068         1165        >20.7
m2                4743        12296         1279        >21.8
w2                5769         7329          318        >20.2
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #22362
V. Cunningham, J. D. Neill, S. B. Cenko, and R. Walters report on behalf of the SEDM team:
We obtained a spectrum of the optical afterglow of GRB181105A (Cannizzo et al., GCN 22335; Cano et al., GCN 22345; de Ugarte Postigo et al., GCN 22346; Marshall et al., GCN 22357) with the Spectral Energy Distribution Machine (SEDM) on the 60 inch telescope at Palomar Observatory. The SEDM is a low resolution (R ~ 100) integral field unit spectrometer with a multi-band (ugri) =E2=80=9Crainbow=E2=80=9D camera imager (see Blagorodnova et al., 2017, astro-ph/1710.02917).
Observations began at 4:30 UTC on January 15 (14 minutes after the Swift BAT trigger) and covered the wavelength range from 3800-9200 A with an exposure time of 2700 s. Continuum emission is clearly seen at wavelengths redder than 4500 A and is well fit by a relatively steep power-law spectrum with index alpha = 1.93 (f_nu ~ nu^-alpha). No obvious emission or absorption features are clearly detected in the spectrum; due to the low SNR at wavelengths shorter than 4500 A we cannot confirm the detection of Ly-alpha at z = 2.487 reported by de Ugarte Postigo et al. (GCN 22346).

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Jochen Greiner, last update: 18-Jan-2018 [Disclaimer]